Choose PU leather additives by the layer and the first commercial requirement: tactile feel, compatibility-focused polyurethane modification, or general surface control. CHLUMIFE® 3370 is the waxy feel route for solvent/UV systems, CHLUMIAG® 3467 is the compatibility-prioritized route with published PU-modification guidance, and CHLUMIAG® 3565 is a broad surface-control route with a pinhole warning.
The current public facts do not document 3565 as a PU slurry release or release-agent product. Treat it as a surface-control candidate, not a promised demolding solution. For any release complaint, first identify the exact wet-process, dry-process, transfer, embossing, paper-release, or topcoat stage and obtain application-specific supplier evidence.
PU leather additive decision map
| Layer and first requirement | First route | Critical guardrail |
|---|---|---|
| Solvent/UV topcoat needs a waxy or silky tactile profile | CHLUMIFE® 3370 | Dispersion, haze, gloss, abrasion, blocking, print and adhesion |
| PU formulation needs compatibility-focused surface or resin modification | CHLUMIAG® 3467 | Separate coating post-addition from resin prepolymerization; protect reactive balance |
| Water/solvent/UV coating needs broad surface control before curing agent addition | CHLUMIAG® 3565 | Resolve current dosage guidance; watch pinholes, foam, adhesion, and cure |
| Produkt | Published facts | Supplier starting guidance | Important boundary |
|---|---|---|---|
| CHLUMIFE® 3370 | Modified polysiloxane; waxy solid; initial melting point ≥50°C | 0.05–3%; UV and solvent systems | Not published as water-based or as a reactive PU additive |
| CHLUMIAG® 3467 | Modified polysiloxane; 100% active; hydroxyl value ≤85 mg KOH/g | 0.05–1% in solvent coatings; separate water/resin-modification ranges | Compatibility is prioritized; supplier says feel is less refined |
| CHLUMIAG® 3565 | Polyether-modified polysiloxane; 100% active; UV, solvent, and water-based | Public page contains both 0.05–1% and 0.02–3% statements; confirm current TDS | Add before curing agent; pinhole risk; no public PU-release claim |
Define the PU leather layer before choosing
A PU leather construction may include base fabric, porous or compact PU layers, color layers, skin/topcoat, printed effects, embossing, and adhesive or laminate interfaces. A product useful in a solventborne topcoat cannot be assumed suitable for a waterborne skin, wet-process coagulation bath, adhesive, or PU prepolymer.
Record the exact layer, resin, carrier, solids, pigment, crosslinker, catalyst, process temperature, film weight, flash/cure, and downstream operation. Define whether the failure is feel, wetting, leveling, pinholes, blocking, abrasion, flex cracking, print adhesion, release, or another property.
Use 3370 when waxy feel is the target
3370 is a waxy solid for solvent and UV systems, not a water-based route. It is appropriate to screen when the commercial target is a waxy/silky tactile profile in a suitable PU topcoat. Document incorporation temperature, mixing energy, addition order, and cooling history because the published initial melting point is at least 50°C.
Do not approve from hand feel alone. Measure gloss, haze, color, abrasion, mar, blocking, flex, print and adhesive bond, recoating, cleanability, and warm aging. The product page does not support describing 3370 as reactive with PU or isocyanate.
Use 3467 when compatibility is the first risk
3467 prioritizes system compatibility and is listed for water, solvent, and UV systems. The supplier publishes coating-stage use and a separate polyurethane resin-modification route, including addition with the polyol during prepolymerization or later.
Do not collapse those routes into one instruction. Resin modification may affect reactive calculations and polymer structure, while a finished-coating addition is a different experiment. Confirm the intended route and current technical guidance; account for the published hydroxyl value where reactive balance is relevant.
Use 3565 only as a qualified surface-control route
3565 is a polyether-modified polysiloxane listed for water, solvent, and UV systems. The page says it is dispersible in water, oil-soluble, and should be added before the curing agent with thorough stirring. It also warns that similar use may cause pinholes.
The same public page contains two dosage statements—0.05–1% and 0.02–3% of total formulation. Obtain the current technical data sheet and resolve the correct range for the actual system before sampling. Do not present 3565 as a slurry-release route unless the supplier provides application-specific evidence.
Build a layer-specific trial
- Prepare one process-stable control. Hold substrate, PU resin, crosslinker, pigment, solids, viscosity, application weight, flash, and cure constant.
- Choose one layer and one target. Do not compare topcoat feel and base-layer release in the same test.
- Run one additive route at a time. Use a blank plus a compact ladder inside confirmed supplier guidance.
- Condition the laminate. Test after full cure and after the temperature/humidity history relevant to shipment and use.
- Challenge downstream steps. Include embossing, printing, lamination, sewing, gluing, recoating, or cleaning that apply.
Measure tactile, mechanical, and bonding performance
Record tactile ranking with blinded assessors, static/kinetic friction where relevant, gloss, haze, color, leveling, pinholes, foam, block resistance, abrasion, mar, flex, elongation, adhesion between layers, print and adhesive bond, solvent/chemical resistance, hydrolysis/heat-aging results, and odor.
ASTM D1894 covers static and kinetic friction of plastic film and sheeting. ASTM D5178 covers mar resistance on smooth, flat coating surfaces, while ASTM D5402 covers solvent-rub assessment for chemically curing organic coatings and cautions that solvent resistance alone does not prove full cure. Use these only when the specimen and requirement fit; flexible multilayer PU leather often needs customer-specific tests as well.
Avoid common PU leather selection errors
Calling every low-friction result “better feel”
Define the tactile target with reference samples and blinded ranking. Friction data can support the decision but does not capture softness, waxiness, dryness, or warmth by itself.
Using a topcoat additive to solve a release-stage problem
Identify the sticking interface, temperature, pressure, dwell, release paper or mold, resin layer, cure state, and contamination. Request a documented release solution rather than assuming a surface additive has that function.
Ignoring pinholes after surface improvement
For 3565, pinholes are an explicit supplier warning. Repeat foam, pinhole, cure, and adhesion checks at production film thickness and mixing energy.
Related polyurethane and feel guides
Use the 2K PU clearcoat guide for a clearcoat-specific cure and recoatability comparison, the soft-touch guide when tactile coating performance is the primary intent, or the furniture coating guide for rigid wood/board finishing.
Request a PU leather additive comparison
Send the PU chemistry and exact layer, water/solvent/UV system, crosslinker and catalyst, solids and viscosity, substrate, application/transfer method, film weight, flash/cure, required tactile reference, defect photos, current additives, downstream processes, and aging tests. Ask Longchang Chemical to qualify 3370, 3467, or 3565 for the correct layer.